Call transmitter



Sept, 7, 1943. B, D, WILLIS CALL TRANSMITTER Filed Oct. .1, 1941 N w I J BERNARD D.

5 Sheets-Sheet l ATTOR NEYS NVENTOR.

VIILLI B. D. WILLIS Sept. 7, 1943.

QALL TRANSMITTER Filed 001;. l, 1941 3 Sheets-Sheet 2 INVENTOR. BERNARD D. WILLIS BYM 9M ATTO RNEYS.

B. D. WILLIS Sept. 7, 1943.

, 1941 3 Sheets-Sheet 3 on e NO; mmT k m m I." 1 mm m m w H mm mm mm 5 mm um Om 02 mo w o O: m: mm

w x Q 68 INVENTOR. BERNARD D. WILLIS If I 2 g z ATTO RNE YS.

Patented Sept. 7, 1943 CALL TRANSMITTER Bernard D. Willis, Oak Park, 111., assignor toAssociated Electric Laboratories,.lnc., Chicago, III., a corporation of Delaware Application Octoberl, 1941, Serial No. 413,177

15 Claims Thepresent invention relates to call transmitterstzand more particularly to telephone call transmitters adapted for. use in automatic telephone systems of the character oithatdisclosed in'U. S. Patent No. 2,222,131; Bernard DLWillis, granted November 19,1940.

a' conventional automatic telephone :system, the automatic switching. apparatus is selectively controlled in accordance with different digits comprising corresponding different number of impulses. However, in an automatic telephone system of the character'of that disclosed inthe Willis patentmentioned, the'automatic' switchin'g apparatus is selectively controlled in ac- Accordingly, the principalobject of the present invention is to provide a call transmitter which is selectively operative to transmitasingle-impulse of variable time duration corresponding to the outer end of the arbor. l2, a, dial plate M disposed below the finger wheel l3 and an esdiiferent digits, which may be utilized selectively to control the automatic switching apparatus in an automatic telephone system of the type noted.

-Anotherobject of the invention is to provide a call transmitter embodying improved and simplified i'digit con'trol mechanism.

. :."'A further object of the invention is to provide method of operatiomtogether with furtherob- 'jeets and advantages thereof, will best be understood by reference to the following specification taken in connection with the accompanying cutcheon plate 15. The finger wheel l3 has ten finger openings l6 formed-therein which are an ranged in registrywith suitable indicia carried on the dial plate l4. Also, the call transmitter) comprises a finger stop I! secured to the base plate I l and cooperating with the finger'openings l6 formed in the finger wheel I3 to establish a fixed limit position therefor. a

f Also; the calltransmitter HJ comprises a'rear plate l8 secured to the .baseplate in spaced relation thereto by a plurality of studs 19. The rear plate 18 supports a tack of insulating terminal .blocks 20 carrying two spaced-apartcone tact springs 2| and 22. The contact spring 22 is formed of resilient material and normally biased away from the contact spring 2i, fora purpose more fullyexplained hereinafter. A first blockingelement23is pivoted upon the arbor l2 and has anormal position wherein'it engages an insulator 24 carried on the outer end of the, contact spring 22, whereby the contact spring 22 is forced into engagement with the contact spring 2|. Also, a finger lever 25; is pivotally mounted a. normal position and an operated position, the

drawings, in which Figure l isa front view, partly broken away, of a calltransmitter embodying the present invention; Fig. 2 is a rear view of the call transmitter shown in Fig. 1; Fig. 3is afront View in Fig. 3; Fig. 7 isa front view, partly broken away, of a further modified form of the call transmitter; and Figa8is a side view, partly in sectiomof the call transmitter shown in Fig.7.

Referring now moreparticularly to Figs. 1 and "2 0f the drawingathe're is illustrated a telephone call transmitter It] embodying the present invention and comprising a base plate H, a rotatably mounted-arbor l2,"a finger wheel 13 secured to arm 26 of the finger lever 25' being adapted to engage the insulator 24 carried on the outer. end of the contact spring 22 when it occupies its. oper ated position, in a manner more fullyexplained hereinafter. Also, the finger'lever 25 comprises a finger engaging portion or tab 21 which is disposed between the frontsurface of the dial plate 14- and therear surface of the finger wheel l3 in spaced"- relation with respect thereto. More particularly, the finger tab 2! is connected to the body portion of the finger lever 25 by a riser section 28 extending through a slot 29 formed in the base plate ii, the finger tab 2lbeing disposed forwardly and below with respect to the finger stop 11 and re'arwardly and below with respect to the first finger opening l6 formed in thefinger wheel 13. as clearly'shown in Fig. l. 1

Further, the arbor l2 carries a ratchet-wheel 38' on the outer end thereof, the ratchet wheel 30 being rigidly secured to the arbor 12 by an arrangement comprisingaw nut 3| threaded on the outer end of the arbor l2. The finger lever 25, carries a pawl 32 mounted on a pivotal pin 33, which comprises a head '34 adapted to cooperate with the teethdisposed about the periphery of the ratchet wheel 30 and a tail 35 which cooperates-with an outwardly extending pin 3B fixed to the rear plate I8. Also, the pawl 32 carries a spring 31 which cooperates with the pin 36, in a manner more fully explained hereinafter. Further, the ratchet wheel 30 carries a pin 38 which normally engages the first blocking element 23 in order to retain the latter element in its normal position.

Finally the call transmitter Ill comprises a spring motor, not shown, operatively associated with the arbor I2, speed governor mechanism 39 f and ratchet mechanism, not shown, operatively interconnecting the arbor I2 and the speed governor mechanism 39, in a manner more fully ex-v plained hereinafter.

Considering now the operation of the call direction, asviewed in Fig. 2), the arbor I2 is" rotated therewith inthe counterclockwise direction.

Referring now more particularly to Fig. 2, the arbor I2 is rotated in the counterclockwise direction away from its normal position ,an amount corresponding to the digit to be transmitted,

whereupon the associated spring motor, not

shown, is wound. Also, the ratchet mechanism, not shown, interposed between the arbor l2 and the'speed governor mechanism 39 permits free rotation of the'arbor I2 without control by the speed governor mechanism 35. Also,'as the arbor I2 is rotated in the counterclockwise direction, the ratchet wheel 33 is rotated therewith, whereby the pin 38 carried thereby disengages the first blocking element 23 and is moved away therefrom, in the counterclockwise direction, an amount corresponding to the digit to be "transmitted; however, the first blocking element 23 remains in'its normal position in engagement with the insulator 24, thereby to retain the con tact spring 22 in engagement with the contact springZI. i

As the finger opening I6 formed in the finger wheel I3 and receiving the finger of the operator approaches the finger stop 51, the finger of the operator engages the finger tab 21 carried by the finger lever 23; whereby the finger lever 25 is byengages the insulator 24 carried by the contact spring 22' and subsequently engages 'the first blocking element 23'; whereupon the first blocking element 23- is pivoted" in the counterclockwise direction from its normal position'to an operated position. At. this time,-the second blocking element 23 occupies its operated position engaging the insulator 24 carried by the contact spring 22, thereby to retain the contact spring 22 forced into engagement with the contact spring 2 I and the first blocking element 23 occupies its operated position disengaging the insulator 24 carried by the contact spring 22.

Also, when the finger lever 25 is thus pivoted in the counterclockwisedirection about the arbor I2, the pawl 32 is moved therewith; whereby the tail 35 of the pawl 32 disengages the pin 36 and the outer end of the spring 3!v rides up on the pin 36. When the outer end of the spring 31 rides up on the pin 36 the pawl 32 is rotated in a counterclockwise direction about its own pivot pin 33, whereby the head 34 of the pawl 32 is forced into engagement with the teeth disposed about the periphery of the ratchet wheel 39. Accordingly, at this time, the finger lever 25 is locked to the arbor l2 due tothe engagement between the pawl 32 and the ratchet wheel 30.

After the finger opening I6 formed in the finger wheel I3 and receiving the finger of the operator is rotated up to the fixed limit position, as estaboccupies its normal position disengaging the in- 'lished by the finger stop H, the operator withdraws his finger, thereby releasing the finger wheel l3 and the finger tab 21 carried by the finger lever 25. At this time, the spring motor, not shown, associated with the arbor I2 rotates the arbor I2 and the finger wheel I3 connected thereto, in the clockwise direction, back into their normal position. During a preliminary rotation of the arbor. l2 in the clockwise direction toward its normal position, the finger lever 25 is rotated therewith due to the connection therebetween aiTorded by the ratchet'wheel 30 and the pawl 32, as previously explained: Accordingly, the finger lever 25 and consequently the second blocking element 26 are rotated in a clockwise direction with the arbor I2,during the preliminary rotation of the arbor I2 toward its normal position; whereby the second'blocking element 26 is moved from its operated position back to its normal position, wherein it disengages the insulator 24 carried on the outer end of the contact spring 22. At this time, the first blocking element 23 occupies its operated position'disengaging the insulator 24, and the second, blocking element 2B sulator 2d; accordingly, the. contact spring 122 is moved away from the contact spring 2! due to its'own resiliency, thereby to interrupt a normally completed circuit therebetween.

At'the conclusion of thepreliminary rotation of the arbor I2 in the. clockwise direction, the outer end of the spring 31 carried by the pawl 32 ridesoff of the pin 35 and the tail 35 of the pawl 32 rides up on the pin 36; whereby the pawl 32 is rotated in the clockwise direction about its own pivot pin 33. When the pawl 32 is thus rotated in the clockwise direction about its own pivot pin 33, the head 34 thereof disengages the teeth disposed about. the periphery of the ratchet wheel 30, whereby the finger lever 25 is disconnected'from the arbor IZin order to permit the arbor I2 to be rotated in the clockwise direction back to its normal position without interference.

Also, as. the arbor I2 is rotated in theclockwise irection back to its normal position the ratchet mechanism, not shown, disposed between the arbor I2 and the speed governor mechanism 39 is controlled; whereby the speed governor mechanism, 39 is operatively connected to the arbor I2 in order to efiectthe return rotation of the arbor I2 back to its normal position at a substantially uniform speed. The preliminary rotation oi'the arbor I2 in the clockwise direction back toward its normal position, and prior to the complete operation of the second blocking element 26 from its operated position back to its normal position, permits the arbor I2 and the associated speed governor mechanism 39 to acquire a substantially constant speed before the contact spring 22 disengages the contact spring the pin 38 carried by the ratchet wheel3|| en'- gages the first blockingelement. 23and 'moves itfrom" its operated position ba'ck to its normal position; wherein the first blocking element 23 j engages the insulator carried on the outer end of the contact spring 22, wherebythe contact spring 22 is againforced intoengagement with the contact spring 2|. i

.."In view of the foregoing" explanation :of the mode of operation of the call transmitter |0,it

will be understood that'the contact springs 2| and 22 occupy their open-circuit position during .a time'interval which corresponds to the time interval required by the arbor |2 to return from its operated position to its normal pcsition after the second blocking-element zfiisoperated back to its normal position, which time .interval is under the 1 control of the speed governor mechautilized. Accordingly, when any given digit, is dialed on the finger wheel l3 by the operator the call transmitter it operates. to transmit a single impulse comprising an open-circuit period which is directly proportional to the digit dialed.

jI-Ience, the call transmitter It is selectively operative to transmit a single impulse of. variable time duration corresponding to the diiferentdigits.

Referring now more particularly to Figs. 3 to .6,

, inclusive, of the drawings, there is illustrated a modified form of the call transmitter 55 embodying the present invention and-comprising a base plate 5|, a rotatably mounted arbor 52, a finger Q wheel 53 secured to the outer end ofthe arbor 52 and adial plate 55 disposed below the finger Wheel 53. The finger wheel 53 has ten finger openings 53a formedtherein which are arranged in registry with suitable indicia carried on the dial plate 54. Also the call transmitter 50 com [prises a finger stop 55 secured to the base plate 5| and cooperating with the finger openings 53a formed in the finger wheel 53 to establish a fixed limit position therefor. i

The rear surface of the base plate 5| supports a stack of insulatingterminal blocks 55 carrying two spaced-apart contact springs '51" and 58. The

. contact spring 58 is'formed of resilient material and normally biased away from. the contact 1 spring 51, for a purpose more. fully explained hereinafter. An arcuate-shaped slot 59 is formed in the base plate 5! and supports a slidably mounted insulator 55 therein. The insulator 60 constitutes a first blocking elementgwhich has a normal position wherein it engages an insulator 5 i carried on the outer end of the contact spring :58, whereby the contact spring 58 is forced into LA pin 55a is secured to the arbor 52 and normally engages the first blocking element 50, in order to retain the latter element in its normal position.

engagement with the contact spring 57.

Also a finger lever 62 is pivotally mounted on the arbor 52 and comprises an extended arm 63 projecting into theslot 59 formed in the base plate 5| and constituting a second blocking element having a normal position and an operated position, the arm 63 of the finger lever 62 being adapted to engage the insulator 6| carried on the outer end of the contact spring 58 when it occupies its operated position, in a manner more fully explained hereinafter. Also .the finger lever 62 comprises a finger engaging portion or tab 64 which is disposed between the front surface of the dial plate '54 and the rear surface of the finger wheel 53 in spaced relation with respect thereto. More particularly, the finger tab '64 is disposed forwardly and below with respect to the finger stop 55 and rearwardly and below with respect to the first finger opening 53a formed in the finger wheel 53, as clearly shown in Fig. 3. The finger lever 62 is, biased in a counterclockwise direction about the. arbor 52, as viewed in Fig. 3, by a resilient spring 65 secured to the front surface of the base plate 5| bya plurality of screws 56.- Also,the finger lever 62 slidably supports a pin 61 in an opening formed therein, the head of the pin 61' being adapted .to engage and cooperate with a rounded projection 88 formed on the front/surface of the base plate 5|, in a manner more fully explained hereinafter.

Further, the call transmitter 55 comprises a spring motor 69 operatively; associated with the arbor 52, speed governor mechanism 15 and ratchet mechanism, not shown, operatively interconnecting the arbor 52 and the speed. governor mechanism 10, in a manner more fully explained hereinafter. More particularly, the speed-governor mechanism 10 comprises an operating shaft ll carrying a worm 12; and a cooperating worm gear 13 is rotatably mounted on the arbor 52; the ratchetmechanism, not shown, being disposed between the arbor 52 and the worm gear l3.

Considering now the operation of the call transmitter 55 to transmit a given digit, the operator first places his finger in the appropriate finger opening 53a formed in the finger wheel 53 and rotates the finger wheel 53 in the clockwise direction, as viewed in Fig. 3, up to the fixed limit position as established by the fixed finger stop 55, in accordance with'conventional practice. As the finger wheel 53 is rotated-fin the clockwise direction, as viewed in Fig. 3 (the counterclockwise direction, as viewed in Fig. 5), the arbor 52 is rotated in the counterclockwise direction.

Referring now more particularly to Fig. 5, the arbor 52 is rotated in the counterclockwise direction away from its normal position ,an amount corresponding to the digit to be trans mitted, whereby the associated spring motor 69 is wound. Also, the ratchetmechanism, not shown, interposed between the arbor 52 and the worm gear I3 permits free rotation of the arbor 52 without control by the speed governor mechanism 10. 'Also, as the arbor 52 is rotated in the counterclockwise direction. the pinfilla car ried thereby disengages the first blocking ele ment filland is moved away therefrom, in the counterclockwise direction. an amount corre sponding to the digit'to be transmittedf however, the first blocking element 65 rema ns in its normal position in engagement withthe nsulator 6|, therebyrto retain the contact pring 58 in engagement with the contact spring 5 fAs the finger Opening 53a formed in the fin er wheel 53 and receiving'the finger of the overator approaches the finger stop 55, the finger of the operator engages the finger tab 64 carried by the finger lever 62, whereby the finger lever 62 is pivoted. in the counterclockwise direction about the arbor .52. As the finger lever ,62 is pivoted in the counterclockwise direction about the arbor 52, the second blocking element 63 carried thereby engages the insulator 6| carried by the contact spring 58 and also thefirst blocking element whereby the first blocking element 50 is slid in the counterclockwise direction in the slot 59 from its normal position to an operated position. At this time, the second blocking element 63 occupies its operated position engaging the insulator 55 carried by the contact spring 58, thereby to retain the contact spring 58 forced into engagement with the contact spring and the first blocking element 65 occupies its operatedposition disengaging the insulator 5! carried by the contact spring 58.

Also, as the finger lever 62 is thus pivoted in the counterclockwise direction about thearoor 52,- the pin 61 carried thereby slides onto the rounded projection 53 carried on the front surface of the baseplate 5| and is forced outwardly toward the. left, as viewed in Fig; 4; whereby the pin 51 looks the finger lever 52 to the finger wheel 53, for a purpose more fully explained hereinafter, I

After the finger oponingg53cz formed in the finger wheel 53 and receiving the finger of the operator is rotated up to the fixed limit posi tion, as established by the finger stop 55, the operator withdraws his finger; thereby releas ing the finger'wheel'53 and the finger tab 55 carried by the finger lever 62. At this time, the spring motor 59 associated with the arbor 52 rotates the arbor 52 and the finger wheel 53, secured thereto, in the clockwise direction back into their normal positions. During the preliminary rotation of the arbor 52 in the clockwise direction toward its normal'position, the finger lever 52 is rotated therewith due to the connection-between the finger lever 62 and the finger wheel 53 afiorded by thepin 51, as previously explained. Accordingly, the finger lever 62 and consequently the second blocking ele-' ment'Bi-l are rotated in a clockwise direction with the'arbor 52, during the preliminary rotation of the arbor 52 toward its normal position;

. whereby the second blocking element 63 is moved is moved away from the contact spring 51 due to its own resiliency, thereby to interrupt a normally completed circuit therebetween. I

At the conclusion of the preliminary rotation of the arbor '52 in the clockwise direction, the

head of the pin '61 rides off of the rounded projection 68 carried on the front surface of the base plate 5| and falls, due to the action of gravity, tothe right away from the finger wheel 53, as viewed in Fig. 4, thereby to unlock the finger lever 62 from the finger wheel 53 in order to permit the arbor 52 and the finger wheel 53 connected thereto to be rotated in the clockwise direction back to their normal positions without interference. Also, as the arbor 52 is rotated in the clockwise direction back to its normal position, theiratchet mechanism, notshown, disposed between the arbor 52 and the worm gear 13 is controlled; whereby the worm gear 13 is operatively connected to the arbor 52 in order to effect an operative connection between the arbor 52 and the speed governor 75. Accordingly, the speed governor Iii effects the return rotation of the arbor 52 back into its normal position at a substantial uniform speed. Thezpreliminary rotation of the arbor 52 in the clockwise direction back toward its normal position, and prior to the complete operation of the second blocking element 63 from its operated position back to its normal position, permits the arbor 52 and the associated speed governor Hi to acquire a substantially constant speed before the contact spring 58 disengages the contact spring 51.

Finally, when the arbor 52 is returned in the clockwise direction back to its normal position, the pin a carried thereby engages the first blocking element 50 and slides it in the clockwise direction in the slot 59 from its operated position back to its normal position; wherein the first blocking element 65 engages the insulator 6| carried' on the outer end of the contact spring 58, whereby the contact spring 58 is again forced into engagement with the contact spring 51.

In view of the foregoing explanation of the mode of operation of the call transmitter 50, it will be understood that the contact springs 57 and 53 occupy their open-circuit position during a time interval which corresponds to the time interval required by the arbor 52 to return to its normal position after the second blocking element 68 is operated back to its normal position, which time interval is under the control of the speed governor Ill and is directly proportional to the initial rotation of the finger wheel 53 away from its normal position; which intial rotation of the finger wheel 53' away from its normal position is determined in accordance with the fin ger opening 531: formed in the finger wheel 53 which is-utilized. Accordingly, when any given digit is dialed on the finger wheel 53 by the operator, the call transmitter 59 operates to transmit'a single impulse comprising an open-circuit periodwhich is directly proportional to the digit dialed. Hence, the call transmitter 58 is selectively operative to transmit a single impulse of variable time duration corresponding to the different digits.

Referring now more particularly to Figs. '7 and 8 of the drawings, there is illustrated a further modified form of the call transmitter 55' embodying the present invention and comprising a cup-shaped enclosing casing 81 supporting a stationary stud 82, a cover or dial plate and a finger wheel 84 rotatably mounted on the stud 82. The finger wheel 84 has twelve finger open- I ings 85 formed therein which are arranged in registry with suitable indicia carried on the dial plate 83. Also, the call transmitter 85 comprises a finger stop 85 secured to the casing 81 and cooperating with the finger openings 85 formed in the finger wheel 84- .to establish a fixed limit position.

The finger wheel 85 carries a centrally located cylindrical skirt 3? whichextends through a circular opening 88 formed in the dial plate 83 into the interior of the casing 35. A tubular bushing 89 is rotatably mounted on the stud 82 and carries a gear and a ratchet wheel 9! disposed in spaced-apart relation. Also, a tubular bushing 92 is rotatably mounted on the stud 82 and carries a worm gear 93. A pawl 55 is pivotally mounted on a pivot pin 95 carried by the worm gear 93 and biased in a clockwise direction, as viewed in Fig. 7, by a surrounding coil spring 95. More particularly, the pawl 5 is biased by the I coil spring 96 into engagement with the teeth disposed about the periphery of the ratchet wheel 9!, for a purpose more fully explained hereinafter.

Also, the call transmitter 58 comprises a speed governor 91, including a rotatable shaft 98 car,-

the spindle I I.

rying a worm 09 whichis meshed with the teeth disposed about the periphery of the Worm gear 93. Also housed in the casing H is a spring motor comprising a coil spring I00, a spindle IOI and a collar I02, the opposite ends ofthe coil spring I00 being secured, respectively, to the collar I02 and to a pinion I03 rotatably mounted on Also, it is noted that the teeth disposed about the periphery of the pinion l03 engage the teeth disposed about the periphery of the gear 90, for a purpose more fully explained hereinafter. The collar I02 comprises atubular portion I00 which extends through an opening I formed in the bottom wall of the casing BI and carries an adjusting wheel I06 on the outer end thereof. More particularly, the tubular portion I04 of the collar I02 frictionally engages the surrounding surface of the opening I05 formed in the bottom wall of the casing 8i and may be rotated against thefrictional engagement by the adjusting wheel I06 in order to vary the initial stress exerted upon the coil spring ,I 00. Further, the bottom wall of the casing 8| carries a bracket I01 which supports a stack of insulating terminal blocks I08 which carry two spaced-apart contact springs I00 and H0. The contact spring H0 is formed of resilient material and is normally biased away from the contact spring I09, for a purpose more fully explainedhereinafter. The gear 90 carries an'upwardly offset and outwardly extending arm III constituting a first blocking element having a normal position, wherein it engages an insulator I2 carried intermediate the ends of the contact "spring-H0; whereby the contact spring I I0v is forced into engagement with the contact spring tact spring IIO, whereby the contact spring I I0 is further forced into engagement with the contact spring I00. Also the finger lever II 3 carries a finger engaging portion ortab I I6 which "is disposed between the front surface of the dial plate'83 and the rear surface of the finger wheel 84 in spaced relation with respect theretof More particularly, the finger tab H6 is dispdsedforwardlyand below with respect to the finger stop 7 86 and rearwardly and below with respectto the finger opening 85 formed in the finger wheel 84 and arranged in registry with the index 1 carfried on the dial plate 83, as clearly showniriFig.

7. Also, it is noted that the finger lever I3 isnormally biased in the counterclockwise direction by a resilient leaf spring II1 extending between the stud 82 and the finger lever H3. j

Further, the bottom wall of the casing! car- -ries a substantially U-shapedbracket II8 which supports a pivot pin IIS upon which a control lever I20 is pivotally mounted. The control lever I20 is normally biased in the counterclockwise direction about the pivot pin H9, as viewed in Fig. 7, by a leaf spring I2! extending between the control lever I20 and the pivot pin I I9. The

control lever I20 comprises a rearwardly extending arm I22 which cooperates with'the insulator I I5 carried on the outer end of the contact spring I I0, in a manner more fully explained hereinafter, I

bular member attached thereto is rotated thereand aforwardly extending arm I23 which supports a rotatably mounted shaft I24., The shaft I24 carries a geared pinion I25 on the lower end thereof and a friction pinion I26 on the upper end thereof, The teeth disposed about the periphery of the geared pinion I25 normally engage the teeth di'sposed about theperiphe'ry of the gear 90; while the friction surface of the friction pinion I26 normally engages'a friction surface I21 disposed about the lower end of the skirt '81 carried by the finger wheel 84. Preferably, the friction surface formed on the friction pinion I26, as well as the friction surface I21 formed on the skirt 81, are provided thereon by knurling or serrating the surfaces mentioned. Accordingly, theshaft I24 is forced toward the skirt 81 and the gear 90 'due -to the'bias of the control lever I20 in the counterclockwise direction about the pivot pin H9, as viewed in Fig.7, as previously noted;' whereby. the friction surfaceof the friction pinion I20 normally engages the friction surface I21 disposed about the skirt .81 and the teeth disposed about the. periphery of the geared pinion I25 normally engage the teeth disposed about the periphery of the gear 90. Finally, the side wall of thecasing BI carriesa bracket I28 which'supports a pin I29 upon which a roller I30 is' mounted. The arm III is carried by the gear 90 normall'yengagesthe roller, I30, thereby to'retain the gear 90 in its normal position.K i I In view of. the foregoing descriptionof the construction and arrangement of the call transmitter 80, it will be understood thatthe coil spring I00 normally biases the pinion I03 in a clockwise di- '7; whereby thegear. 901s biased in'a counterclockwise direction'about the stud 82,.as viewed in Fig. 7, in order enforce the arm III carried by the gear 90into engagement with the roller I30 mounted on the'pin I29.

Considering now theoperation of the call transmitter totransm'itagiven digit, the operator first places his finger in the appropriate finger opening formed in the finger wheel 84 and rotates the finger wheel 84 in the clockwise --direction, as viewed in Fig. 7,up tothe fixed limit position as established by the finger stop 86, in accordance withconventio'nal practice. As the finger wheel 84'is rotated in the clockwise direction, as viewed in Fig. '1, the attached skirt Ill-is rotated therewith. The rotation of the skirt 81 in the clockwise direction rotates the shaft 24 in the counterclockwise direction due to the-en- 'gagement between the friction pinion I26 and the friction surface I21 disposedabout the periphery of the skirt 81; whereby the geared pinion I25 carried by theshaft I24 is rotated in the counterclockwise direction. The rotation of the geared pinion I25 in the counterclockwise direction causes rotation of the gear 90 in" the clockwise direction about the stud 82 dueto the engageemnt of the teeth disposed about the peripheryof the geared pinion I25 and the teeth disposed about the periphery of the gear 90.

The rotation of the gear 90 in the clockwise direction effects rotation of the pinion I03 in the counterclockwise direction about the spindle, I or due to the engagement between the teeth disposed between-the periphery of the gear 90 and the teeth disposed about the periphery of the pinion m3. Finally the rotation "of thepinion I03 in the counterclockwise direction about the spindle IOI winds the coil spring I00. Also, as the gear 90 is rotated in the clockwise direction the tuwith; wherebythe teeth disposed. about the periphery of the ratchet wheel 9| carried. by thetuby the worm gear 93. Accordingly, the speed govtact spring IIU to an operated position Accordingly, formed in the finger wheel 84 and receiving the against the bias of the leaf spring I2I. the control lever I20 is thus rotated in the clockernor mechanism 9'! permits free rotation of the gear 90 in the clockwise direction about the stud 82. 1

Also, as the gear 99 is rotated in the clockwise direction about the stud 82, the first blocking element HI carried thereby is rotated therewith away from its normal position engaging the insulator H2 carried intermediate the ends of the contact spring IIIito an operated position and an amount corresponding to the digit to be transmitted; however, the second blocking element H4 remains in its normal position in engagement with the insulator H5 carried on the outer end of the contact spring III thereby to retain the contact spring I II! in engagement with the contact spring I09. As the finger opening 85 formed in the finger wheel 84 and receiving the finger of the operator approaches the finger stop 86, the finger of the operator engages the finger tab H6 carried by the finger lever H3, whereby the finger lever H3 is pivoted in the clockwise direction about the stud 82. As the finger lever I I3 is pivoted in the clockwise direction aboutsthe stud 82 the second blocking element H4 carried thereby is rotated therewith away from its'normal position engaging the insulator H5 carried on the outer end of the condisengaging the insulator I I5.

when the finger opening 85 finger of the operator is rotated up to the fixed limit position, as established by the finger stop I86, the finger lever II3 isfully moved; thereby to operate the second blocking element H4 from its normal position to its operated position.

.When the second blocking element I I4 is thus moved to its operated position the insulator H5 wise direction about the pivot pin H9 the shaft I24 is moved away from the skirt 3'! and the gear 80, whereby the friction pinion I26 disengages the friction surface I21 disposed about the periphery of the skirt 81 and the geared pinion I2 5 disengages the gear 90. Accordingly, at this time, the connection between the skirt 81. and the gear 9!! is broken.

j When the gear 90 is thus disconnected from .the skirt 8? the pinion I03 is free to rotate in the clockwise direction about the spindle IEII under the control of the coil spring I00. Therotation of the pinion I93 in the clockwise direction about the spindle IDI effects rotation of the gear Bil in the counterclockwise direction about the stud 82 due to the engagement between the teeth disposed about the periphery of the pinion I83 and the teeth disposed about the periphery of the gear 96. -Accordingly,. the gear 90 is rotated in thecounterclockwise direction about the'stud 82 back into its normal position, whereupon the "first blocking element III carried thereby engages the roller I30 mounted on the pin I29; thereby to arrest further rotation of the gear 90 When in the counterclockwise direction and further rotation of the pinion I93 in the clockwise direction. Moreover, when the first blocking element I II carried by the gear 90 is returned to its normal position the insulator I I2 carried intermediate the ends of the contact spring HE] is engaged thereby; whereby the contact spring H0 is again forced into engagement with the contact spring I89. Also, when the contact spring H6 is moved toward the contact spring I09 the insulator H5 carried on the outer end of the contact spring I I0 disengages the arm I22 of the control lever I26; whereby the control lever I20 is rotated in the counterclockwise direction about the pivot pin H9 by the leaf spring I28. When the control lever I28 is thus rotated in the counterclockwise direction about the pivot pin H9 the shaft I24 is again returned toward the skirt 81 and the gear 90, whereby the friction pinion I28 reengages the friction surface I2'II disposeda-bout the periphery of the sln'rt 81 and the teeth disposed about the periphery of the geared pinion I25 reengage the teeth disposed about the periphery of the gear 9%.

At this pointit is noted that the finger wheel gaged finger-opening 85 formed therein, when 2 his finger is brought into engagement with'the finger stop 86 the finger lever H3 is latched in its operated. position by the cooperation between the second blocking element H4 carried by the finger lever IE3 and the insulator H5 carried on the outer end of the contact springv I Ii]. More particularly, when the second'blocking element IM is moved from its normal position to its operated position the insulator H5 is moved toward the stud 82 and behind the second blocking element H4, thereby to latch the finger lever H3in its operated position. Subsequently, when the gear 90 is returned to its normal position and the first blocking element I I I carried thereby engages the insulator H2 carried intermediate the ends of the contact spring IIEI, the insulator I I5 carried on the outer end of the contact spring H0 ismoved away from the stud 82. When the I 85'f0rmed in the finger wheel 84, when his finger engages the finger stop 86 the mechanism housed in the call transmitter operates, in the manner explained above; except that the finger lever H3 is not automatically returned in the counterclockwise direction back to its normal position after the digit has beentransrnitted by the call transmitter 88 until-the operator withdraws his finger from the engaged finger opening formed in the finger wheel 84, in an obvious manner.

JV When the gear 98 is rotated in the counterclockwisedirection back toward its normal position the tubular member 89 and the ratchet wheel .SI secured; thereto are rotated therewith. When the ratchet wheel SI'I is thus rotated in the counterclockwise direction about the stud 82, the teeth disposed about the periphery of the ratchet .wheel SI engage the associated pawl 92, thereby to lock the worm gear 93, to the ratchet wheel EH for rotation therewith. Accordingly, as the gear 90; is rotated in thecounterclockwise direction back to its; normal position, the worm gear sponding to the difierent digits.

While one embodiment ,of the invention has beendisclosed, it will be understood that various 9311s rotated, in the counterclockwise direction about thestud 82' therewith. 'This rotationiof" thelworm gear 93 in the counterclockwise direc-' tion effects rotation of the operating shaft 98 of the speed governor mechanism 91; whereby the speed governor mechanism 91 effects the return rotationof the gear back to its normal position at a substantially uniform speed. l view of the foregoing explanation ofthe' modeof operation of the call transmitter 80, it

will be understood that the contact springs I09 and H3 occupy their open-circuit position dur ing a time interval which corresponds to the time interval required by the gear"90 to return proportional to the initialrotation of the finger wheel 8-4 away from its initial position; which'in itialrotation of the finger wheel 84 away from.

its initialposition is determined in accordance with the finger opening 85 formed in the, finger Wheel 84 which is utilized- Accordingly, when any given digit is dialed on the finger wheel 84: by the operator the call transmitter 80 operates transmit a single impulse comprising an open-circuit period which is directly propor-- tional to the digit dialed. I-IenceQthe call transmitter M is selectively operative to transmit a,

single impulse of variable time durationcorremodifications maybe made therein which are within the true spirit and scope of the invention. WWhat is claimed is:

1. A call transmitter adapted transmit a single impulse of variable time duration corresponding to different digits comprisingvariably operable digit register mechanism, a timer, means responsive to the registration of' a digit in said digit register mechanism and controlled in accordance with theparticular-digit registered therein for operating said timer through a fixed cycle of a corresponding time .durationffa pair of ,contactshaving a normal position, and means governed by said timer for operating saidcontacts away from their normal position at the beginning of saidcycle and for operating said contacts back to their normal position at the end of said cycle, whereby said contacts are operated to a: rotatably mounted member having a normal position, means responsive to rotation of said finger Wheel in accordance with a given digit for rotating said member away fromits normal position an amount corresponding to saidgiven digit,

a pair of contacts having a normal position,

means for initiating return rotation of said mem ber back to its normal position and for operating said contacts away from their normal positiommeans responsive to, the returnof said mem- 1 her to its normal position for operating said coni tactsback to their normal position, and governor j means ioryefiecting the return rotation of said member back to its normal position at a substantially uniform speed, whereby said contacts are operated'away from their normal'positi-on a time interval corresponding to saidgiven digit.

" 3. A call transmittercomprising a rotatably mounted finger wheel variably rotatable up to a fixed limit position in accordance with different digits to be transmitted, a rotatably mounted member having a normal position, means responsive to rotation of said finger wheelup to said limit position in accordancewith a given digit for rotating said member away from its normal position an amount corresponding to said given digit, a pair of contacts having a normal position, meanscontrolledsubsequent to rotation of said finger wheel upitosaid limit position for initiatingreturn rotation 501' said member back to its normal position and for operating said contacts away from their normal position, means respon= sive to the return of said member to its normal position for operating said contacts back to their normal position, and governor means for efiecting the return rotation of said member back to its normal position at-a substantially uniform speed, whereby said contacts are. operated away from their, normal position a timeinterval corre sponding to said given digit; i

4. Awcall transmitter comprising a rotatably mounted finger, wheel variably rotatable up to a fixed limit position in accordance with different digits tobe transmitted, 'a rotatably mounted member having a normal position, means responsive to rotation of said finger wheel up to said limit position in accordance with {a given digitfor rotating said member awayirom its normal position an amount corresponding t-o-said given digit, a pair of contacts having'a normal position, means controlled inresponse to rotation of said finger wheel up to. said limit posi tion and the subsequent release thereof for in'i tiating return rotation of said member back to its normal position and for operating said contacts away from their normal position, means respon sive-to the return of said'memberto its normal position for operating said contacts back to 'their' normal position, and governor means for effect ing the return rotation of. said memberbacktoits normal position at a substantially uniform speed, herebysaid contacts are operated away from their. normal position a time interval correspond ing tosaid givendigit. i

5. A call transmitter comprising arotatably mounted finger wheel variably rotatable up to a fixed limit position in accordance with diiferent digits to be transmitted, a rotatably mounted member having a normal position, means re-- sponsive to rotation of said finger wheelup to said limit position in accordance with a given digit for rotating said member away from its normalposition an amount corresponding to said given digit, means controlled in :response to ro tation of said finger wheel up to said limit position and the subsequent release thereof for ini-' tiatingreturn rotation of said member back to its normal position, a pair of contacts having a normal position, means responsive to a prelim: inary rotationof said member back-toward its normal position for operating said contacts away from their normal position, means responsiveto the return of said member to its normal position for-operating said contacts back to their normal position, and governor means for effecting the return rotation of said memberback to its normal position at a substantially uniform speed; whereby said contacts are operated away from their normal position a time interval corresponding to said given digit. a

6. A call transmitter comprising a rotatably mounted finger wheel variably rotatable up to a fixed limit position in accordance with difierent digits to be transmitted, a rotatably mounted member having a normal position, means responsive to rotation of said-finger wheel up to said limit position in accordance with a given digit for'rotatingsaid member away from its normal position an amount corresponding to said given digit, a pair of contacts having a normal position, a first blocking element normally restraining said contacts in their normal position, a second blocking element adapted to restrain said contacts in their normal position, means controlled in response to rotation of said finger wheel up to said limit position for removing said first blocking element and for placing said 'second blocking element, means responsive to subsequent release of said finger wheel for initiating return rotation of said member back to its normal position, means responsive to a preliminary rotation of said member back toward its normal position for removing said second blocking element, whereby said contacts are operated away from their normal position, means responsive to the return of said member to its normal position for-replacing said first blocking element, whereby said contacts are operated back to their normal position, and governor meansfor effecting the return rotation of said member back to its normal position at a. substantially uniform speed, whereby said contacts are operated away from their normal position a time interval corresponding to said given digit.

'7. A'call transmitter comprising a rotatably mounted finger wheel variably rotatable up to a fixed limit position in accordance with different digits to be transmitted, a rotatably mounted memberhaving a normal'position, means responsive to rotation of said fingerwheel up to said limit position in accordance with a given digit for rotating said member awayfrom its normal position an amount corresponding to said given digit, a pair of contacts having a normal position, a first blocking element normally restraining said contacts in their normal position, a sec ond blocking element adapted to restrain said contacts in their normal position, means including a finger lever controlled in response torotation of said finger wheel up to said limit position for removing said first blocking element and for placing said second blocking element and for connecting said second blocking element to said member, means responsive to subsequent release of said finger wheel for initiating return rotation Y of said member back to its normal position, means responsive to a preliminary rotation of said member back toward its normal position for removing said second blocking element and for disconnecting/said second blocking element from said member, whereby said contacts are operated away from their normal position, means including a part carried by said member and responsive to the return of said member to its normal position for replacing said first blocking element, whereby'said contacts are operated back to their normal position, and governor means for effecting the return rotation of said member back to its normal position at a substantiallyuniiorm speed,

whereby said contacts are operated away from their normal position a time interval corresponding to said given digit. I

8. In a call transmitter, a rotatably mounted fingerwheel variably rotatable up to a, fixed limit position in accordance with different digits to be transmitted, a rotatably mounted member having a normal position, means responsive to rotation of said finger wheel up to said limit position in accordance With a given digit for rotating said member away from its normal position an'amount corresponding to said given digit, a first control element having a normal position and an operated position, a second control element having a normal position and an operated position, the normal position of said first control element and the'operated position of said second control element constituting a common position, means responsive' to rotation of said finger wheel up to said limit position for moving said second control element from its normal position to its operated position, thereby to force said first control element from its normal position to its operated position, and for locking said second control element to said member, means responsive to subsequent release of said finger wheel for initiating return rotation of said member back to its manual position, means responsive to a preliminary rotation of said member back toward its normal position for operating said second control element from its, operated position back to its normal position and for unlocking said second control element from said member, mean responsive to the return of said member to its normal position for operating said first control element from its operated position back to its normal position, and digit transmitting means selectively operated by said first and second control elements.

9. A call transmitter comprising a rotatably mounted finger wheel variably rotatable up to a fixed limit position in accordance with different digits to be transmitted, a rotatably mounted member having a normal position, a pair of contacts having anormal position, means re sponsive to rotation of said finger wheel up to said limit position in accordance with a given digit for rotating said member away from its normal position an amount corresponding to said given digit and for operating said contacts away from their normal position and for initiating return rotation of said member back to its normal position, means responsive to the return of said member to its normal position for operating said contact back to their normal position, and governor means for effecting the return rotation of said member back to its normal position at a substantially uniform speed, whereby said contacts are operated away from theirnormal position a time interval corresponding to said given digit.

10. A call transmitter comprising a rotatably mounted finger wheel variably rotatable up to a fixed limit position in accordance with difierent digits to be transmitted, a rotatably mounted member having a normal position, means responsive to rotation of saidfinger wheel up to operating said contacts back to their normal position, and governor means for effecting the returnrotation of said member back to its normal ".position at asubst'antially uniform speed,

whereby said contacts areoperated' away from their normal position a time interval corresponding to said given digit.

11. A call transmitter comprising a rotatably mounted finger Wheel variably rotatable up to 11 a'fixed limit position in accordance with diifer- V ent digits to be transmitted, a rctatablymounted member, having a normal position, means r'espons i sive to rotation of said finger wheel up to said limit ;-position in accordance with a given 'digit n for rotating said member away from its normal. position an amount corresponding to said given g Qdi'git, a pair of contacts having a normal position, means includinga finger lever responsive to rotation of said finger wheel up to said limit pon 9 tor, means responsive to rotation of said finger wheel up to said limit position for disconnecting said memberirom said fingerwheel, means in--,

cluding said spring motor'and responsive to the disconnection of said member from said finger said member to its normal position for reconnect member;

sition for operating said contacts away from their normalflposition, means responsive to the, f

effectingthe returnrotation of said member back to its normal position at a substantially uniform speed, whereby said contacts are operated away member having a normal position, means re- I sponsive to rotationof said finger wheel upjto said limit position in accordance with a given digit for rotating said member away from its; normalposition an amount correspondingto said 6 given digit, a pair of contacts having anormal position, first and second blocking elements] each normally restrainingsaid contacts in their normal position, means responsive to rotation of said j member away from it normal position for removing said first blocking element, means responsive to rotation of said finger wheel up to said limit position for removing said second blocking lelementywhereby said contacts are operated away 1 operationof said contact away from their normal position for initiating return rotation of said member back to its normal position, means re- 1 sponsive to the return of said member to its normaLpositionfor operating said contacts back to their normal position, and governor means for ing said member to saidfinger wheel, and digit transmitting means selectively controlled by said 14'. In a call transmitter, a rotatably mounted x finger wheel variably rotatable up to a fixed limit to cooperate with clutch elements, respectively carried by aidfinger wheel and bysaid member and normally biased to engage said clutch ele ments, as'pringmotor associated with saidmember, means responsive torotation of said finger wheel up to said limit position in accordance with a given digit for rotating said member through said clutch elements away from its normal position an amount corresponding .to said given digit and for storing energy in a said spring motor,

" means responsive to rotation of said fingerwheel up to said limit position for moving said control leveriagainst its bias, thereby to declutch said clutch elements, means including said spring motor and responsive to the declutching of said i clutch elements forrotating said member back to its normal position, means responsive tO'the return of said member to'its normal position for returning s'aidcontrol lever, thereby to reclutch said clutch elements, and digit transmitting means selectively controlled by said member.

15. In a call transmitter, a rotatably mounted finger Wheel variably rotatable up to a fixed limit position in accordance with different digits to be transmitted, a rotatably. mounted member from their normal positionQand 'for initiatingreposition, means responsive to the returnof said member to its normal position for replacingsaid i first and second blocking elements, whereby said 1 turn rotation of said member back to its normal having a normal position, means normally connecting said "member to said finger wheel, a

spring motor associated with said member, means, Q responsive to rotation of saidfinger wheel up to said limit position inaccordance with a given digit for rotating said member away from its normalposition an amount corresponding to said contacts are operated back to their normalposii tionyand governor means for eiiecting the return rotationlof said member back to itsnormal position at a substantially uniformspeed'whereby said contacts are operated away from their normal position a time interval corresponding to said given digit. Y

given digitand forstoring energy in said spring motor, a finger lever having a normal position,

meansresponsive to rotation of said finger wheel up to said limit position for moving said finger lever away from its normal position, means responsivejto movement of said finger lever away from its normal position for looking it out of its normal position and for disconnecting said mem- 13, In a call transmitter, a rotatablymounted finger wheel variably rotatable in the same direction up, to a fixed limit position inaccordance' finger wheel up to said limit position in accordance with a given digit for rotating said member with different digits to be transmitted, a rotatt I ably mounted member having a normal position, ll jmeans normall connecting said member to said i finger-wheel, a spring motor associated with said member, means responsive to rotation of said mil-ting her from said finger wheel, means includin said spring motor and responsive to the disconnection of said member from said finger wheel for rotat ing said member back to its normal position, :means responsive to the return of said member to its normal positionfor Tunlocking said finger lever and forreturning it to its normal position, means responsive to the return of said finger lever to its normal position for reconnecting said member to said finger wheel, and digit transmember.

BERNARD D. WILLIS.

means selectively controlled by said 

